leffingwell



' tnbad mes O. LEFFINGWELL, OF ZANESVILLE, OHIO,.IASSIGNOR 'IO HIMSELF, H.

" BLANDY, AND F. BLANDY, OF SAME PLACE.

Letters Patent No. 97,302, dated November 30, 1869.

4nvmno'vmvmn'r 1N Hnannocxs ron saw-MILLS.

' The Schedule referred to these Letters latent' and making part ofthe name To all whom it may concern:

Be it known that I, C. LEFFINGWELL, of Zanesville, in the county of Muskingum, and State of Ohio, have invented a new and useful Improvement in Saw- Mill Head-Blocks; and' I do hereby declare'that the following is a full, clear, and exact description thereof, which will' enable others skilled in the art to make and use the same, reference being had to the accompanying drawings, forming part of this specification.

This improvement consists in the arrangement of the three levers, in combination with the two doubley faced ratchebwheels, with their respective pawls, so.

arranged that the operator, without changing position, `can set either block separately, or both blocks together, without lthrowing anything in or out of gear.

In the accompanying plate of drawings- Figure 1 represents a planv view of the head-block,l arranged on the mill-carriage, as when in use, but shown partly in section.

Figure 2 is a vertical crosssection of iig. l, through the line :t x.

Similar letters of reference indicate corresponding parts. v

.A is the carriage, and B B represent the-headblocks, which slide freely thereon, so that they may be adjusted to logs of different length.

C represents a vertical stand upon each headblock, connected with and forming part of a horizontal slide, I), which is connected with the head-block by means of grooves and tongues, and slides back and forth freely thereon. l

' Upon the under side of the horizontal part D there.

F F represent shafts, on""each of which there is a pinion, Gr', which works in the racks E.

In tig. 1, the slide D is broken away in the drawing, to show one of these pinions, G.

The shafts F F' pass through the head-blocks, and are supported thereby.

Their inner endsare supported bystands attached to the carriage.

Thereis a groove in each shaft, and a feather in each of the pinions G, which engage with the grooves, and allow the shafts to slide through the pinions, so that the head-blocks may be moved nearer together or further apart,according to the length of the logs to he sawed.

H H represent ratchet-wheels on the shafts F F.

Each ratchet has a lever, I, and pawl J, by which its shaft may be revolved independently of the other, which would, ofcourse, allow either end of the log to he moved, while the other end remained stationary. l

K is a central lever, with two pawls, L L, one of which engages with each ratchet, by which the two shafts are revolved simultaneously.

The inner ends of the two shafts meet in the eye or hub of the central lever K, which hub forms a loose collar, in which the shafts easily turn.

The number of teeth on the ratchet-wheel HH exactly corresponds with the number of eighths of an vinch iu the circumference of the rack-pinions G, thereby causing each tooth to throw or move the stands G and the log one-eighth of an inch, so that eight teeth on the ratchet make exactly one inch on the face ofthe head-block.

The ends of the levers I I form loose collars th rough which their respective shafts pass.

By the arrangement described, either or both ends ofthe log may be moved by a single motion, without the trouble of connecting, or disconnecting, or throwe ing anything into or out of gear, or dropping or lifting any pawls.

The movement of the pawl-levers I I and K, or of either of them, is regulated by the curved guides N,

`one to each lever, an elevation of which is seen in iig. 2.

O is an adjustable forward stop ou each of the P represents movable backward stops, so arranged that each one corresponds exactly tooue tooth. ofthe ratchet-wheels, and one-eighth oi' an inch on the headblock. A

The drop-pawls J are so adjusted, as to length, as to drop exactly against a tooth in the ratchet-wheel,

'when the lever is bronghtagainst the forward stop O, which entirely prevents any back motion in the stands C.

Thestops I? are so adjustefhthat when `the lever is thrown backmthe distance required for thethickness of the lumber being sawed, thelever-pawls, J, will rest on about the middle of the tooth next hack of thel tooth engaged by the pawlJ, thereby preventing danger of ever missing a tooth on the ratchet.

l This arrangement of the pawls is secured by the adjustable forward stop O, by which the distance between it and the back stops may be increased or diminished.

When the levers are all brought forward against the Vstops O, the lever-pawls are so constructed and adj usted that they stand in line with each other.

'The drop-pawls J alsovsiand in the same position.

as regards each other.

I am aware of the patent granted to T. S. Clark, March 10, 1868, and that to J. F. Cook, December 15, 1868, for improvements in head-blocks, but I do not desire to claim anything shown therein; but

What I do esteem to be'myiuvention, and desire to secure by Letters Patent, is-

'Ihe arrangement of the levers I. I K, double-faced ratchetwheels H, and pawls J, iu the manner shown and described, and for the purpose specified.

(E. LEFFINGWELL.

Witnesses:

E. BALLOU, JOHN J. AsTnN. 

